COUPLE BRINGS FINE TASTES OF THAILAND TO HIGHLAND PARK

Nittaya and Kitisak Visalvanich are culinary pioneers. On March 28, 1991, they opened Thai Image, Highland Park`s first Thai restaurant.

''When the space in the Optima Center adjacent to Port Clinton Square became available, we felt it would be an ideal location,'' Nittaya recalled.

''Restaurants in Highland Park do well throughout the week, and area residents seem to have a real appetite for Oriental food.''

The restaurant`s decor is sleek and comfortable, distinguished by a tasteful display of Thai artwork and artifacts. To accommodate American palates, the Visalvaniches have toned down the sizzle traditionally associated with Thai cooking. Guests who like fiery fare should ask to have the heat turned up.

Knowing a little about the cuisine facilitates decisionmaking, though the explanations offered on Thai Image`s menu are quite helpful. For starters, the Thais season their food with fish sauce (nam pla), a salty liquid made from fermented anchovies. Lemon grass, coconut milk and coriander (cilantro) also play a prominent role in many Thai dishes. And, unlike the Chinese, Japanese, Koreans and Vietnamese, the Thais eat with a fork and spoon, not chopsticks.

Rice is a staple of the Thai diet, and no meal is considered complete without it. A recent meal began with an order of spring rolls done with a vegetarian filling and a soft, crepe-like wrapper. Sweet-and-sour plum sauce and a sprinkle of green onions completed the presentation. Tom yum soup strewn with shrimp and seasoned with lemon grass and fresh lime juice came next. The yum talay salad featured a mix of seafood and a sprightly dressing seasoned with chili powder, lime juice and lemon grass.

Thai Image`s red snapper is deep-fried, partially boned and served with a choice of sauces. According to Nittaya, the most emphatically Thai of the sauces is made with hot peppers, garlic, chili paste and stir-fried vegetables. Both a sweet-and-sour and a ginger sauce also are available.